Oil tanker traffic through the Panama Canal has jumped in recent weeks as Asia scrambles to buy U.S. crude amid choked supply from the Middle East. The Panama Canal, the fastest route for American energy exports to Asia on smaller vessels, is at its busiest for U.S. crude exports in four years as the closed Strait of Hormuz has forced Asian buyers to source oil from regions other than the Middle East. The price of booking a last-minute slot to have a tanker pass through the Panama Canal has nearly tripled to almost $400,000 since the Iran war began,…